<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>1.demo</title>
</head>
<body>
    <button>测试1</button>
    <button>测试2</button>
    <button>测试3</button>
    <button>测试4</button>




    <script src="https://cdn.bootcdn.net/ajax/libs/jquery/1.10.0/jquery.min.js"></script>
    <script>
         $(function(){
            // console.log( $("button").size());

            $("button").each((i,e)=>{
                console.log(i,e);
            })
         })
    </script>

</body>
</html>